Real-time emission characterization of organic air toxic pollutants during steady state and transient operation of a medium duty diesel engine
Real-time emission characterization of organic air toxic pollutants during steady state and transient operation of a medium duty diesel engine
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DOI：
10.1016/j.atmosenv.2006.03.031
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发表时间：
2006-07-01
影响因子：
5
通讯作者：
Ryan, Shawn P.
中科院分区：
文献类型：
--
作者：
Gullett, Brian K.;Touati, Abderrahmane;Ryan, Shawn P.
采用喷射共振增强多光子电离 (REMPI) 和飞行时间质谱 (TOFMS) 在线监测方法来测量中型 (60 kW) 柴油发电机在瞬态和稳态运行期间的有机空气毒物排放。气相苯、甲苯、乙苯、邻二甲苯、间二甲苯、对二甲苯 (BTEX)、苯乙烯和多环芳烃 (PAH) 的排放量在 10-500 ppb 范围内进行测量，测量频率为 10 s(-1)：这使得能够根据运行条件（冷启动、热启动和负载变化）快速表征排放特征。喷气式 REMPI-TOFMS 系统的灵敏度、选择性和实时监测能力可识别出冷启动期间有机空气有毒物质（例如苯和萘）的瞬态浓度超过其稳态水平的 15 倍。通过喷射 REMPI-TOFMS 获得的时间积分浓度与标准 EPA 方法进行了很好的比较。喷气式 REMPI-TOFMS 系统提供了一种快速表征空气有毒物质排放因子的方法，使用户能够改变操作程序以最大限度地减少空气有毒物质的形成。启动和稳态排放之间的相对浓度，以及这些水平之间的过渡期，对于柴油机尾气中发现的每种化合物都是特定的。 (c) 2006 Elsevier Ltd. 保留所有权利。
An on-line monitoring method, jet resonance-enhanced multi-photon ionization (REMPI) with time-of-flight mass spectrometry (TOFMS), was used to measure emissions of organic air toxics from a medium-duty (60 kW) diesel generator during transient and steady state operations. Emissions of gas phase benzene, toluene, ethylbenzene, o-, m-, p-xylenes (BTEX), styrene and polycyclic aromatic hydrocarbons (PAHs) were measured at levels in the 10-500 ppb range with a measurement frequency of 10 s(-1): this enabled rapid emission characterization as a function of operating conditions: cold starts, hot starts and load changes. The sensitivity, selectivity and real-time monitoring capabilities of the jet REMPI-TOFMS system discerned transient concentrations of organic air toxics (e.g., benzene and naphthalene) during cold starts exceeding 15 times their steady state levels. Time-integrated concentrations obtained by jet REMPI-TOFMS compared well with standard EPA methods. The jet REMPI-TOFMS system provides a means to rapidly characterize air toxic emission factors that enables users to alter operational procedures to minimize air toxic formation. The relative concentrations between startup and steady state emissions, as well as the transition period between these levels, were specific for each type of compound found in the diesel exhaust. (c) 2006 Elsevier Ltd. All rights reserved.